Effect of Post-MI Exercise Training on Cardiac Remodeling presentation
1. EFFECT OF POST-MI
EXERCISE TRAINING ON
CARDIAC REMODELING
AND FUNCTION
UNIVERSITY OF TEXAS AT SAN ANTONIO
CARDIOVASCULAR FITNESS – DR. ZHANG
BY: KAYLA FLOYD AND CASTURAL THOMPSON II
2. MYOCARDIAL INFARCTION
• Definition (National Library of Medicine)
• Commonly known as a heart attack that occurs when blood flow to the heart is blocked for a period of time
where the muscle becomes damaged or dies.
• Signs and Symptoms (National Library of Medicine)
• Chest pain
• Pressure, squeezing, or pain
• Shortness of breath
• Discomfort in the upper body
• Arms, shoulder, neck, or back
• Nausea, vomiting, dizziness, lightheadedness, and/or sweating
3. MYOCARDIAL INFARCTION
• Statistics
• 565,000 new cases and 300,000 recurrent cases of MI annually
• People older than 65 have a higher prevalence rate
• More likely to occur in males
• Most victims died before arriving to the hospital
• Is one of the top 5 most expensive conditions for inpatient hospitalization visits in the U.S., approximately
$11.5 billion
10. INTENSITY
• Cannistra et al (1999): Moderate-high intensity
exercise training after myocardial infarction:
effect on left ventricular remodeling.
• 12 week aerobic training program
• Slight variation within the experimental group
• Rognmo et al (2012): Cardiovascular risk of high-
versus moderate-intensity aerobic exercise in
cornonary heart disease patients.
• 6 week training program at high intensities
• There was a reduction in cardiovascular episodes
• Risk: increased chances for the recurrence of MI
or death
11. FREQUENCY
• Nielwand et al (2000): Differential effects of high-frequency versus low-frequency exercise
training in rehabilitation of patients with coronary artery disease.
• 6 week 2 hrs per week training program
• High frequency: 10 per week
• Low frequency: 2 per week
• Higher frequency is associated with functional capacity
• Quality of life
12. DURATION
• La Rovere, Bersano, Gnemmi, Specchia, &
Schwartz (2002): Exercise-induced increase in
baroreflex sensitivity predicts improved
prognosis after myocardial infarction.
• 4 week aerobic exercise regimen
• Decreased cardiovascular mortality by 26%
• Reduced total cholesterol, triglycerides, and
blood pressure
• Lee et al (2008): Effect of cardiac rehabilitation
on myocardial perfusion reserve in
postinfarction patients.
• Increased oxygen consumption
• Increased cardiac output
• Increased regional blood flow
• Increased gene expression
15. CONTRACTILITY – CA2+ SENSITIVITY
• Post-MI patients are at increased risk:
1. Tachycardia
2. Instability in electrical conductance
3. Disturbance in action potential
16. BONILLA ET AL (2012): ENDURANCE EXERCISE TRAINING
NORMALIZES REPOLARIZATION AND CALCIUM-HANDLING
ABNORMALITIES, PREVENTING VENTRICULAR FIBRILLATION
IN A MODEL OF SUDDEN CARDIAC DEATH.
• Exercise:
1. Stablized QTc intervals
2. Reduction action potential duration at 50% and 90% repolarization
3. Restored Ca2+ spark frequency to levels similar to control
18. GENE AND PROTEIN EXPRESSION
• SERCA2a
• ANP
• NCX1 expression
• PLN
• TIMP-1 levels and MMP-1/TIMP-1
• eNOS
19. ACE
• MI causes an increase in ACE and renin levels
• Potent vasoconstrictor
• ACE2 also increases
• Burrell et al (2005): Myocardial infarction
increases ACE2 expression in rat and humans.
• Wan et al (2007): Effect of post-myocardial
infarction exercise training on the renin-
angiotensin-aldosterone system and cardiac
function.
20. FUTURE STUDIES
• Study design
• More women
• Incorporate elderly people
• Longitudinal
• Endurance & resistance training
• Stem cells
http://www.youtube.com/watch?v=vTjc5brpY7A
Symptoms can be different for women (mostly shortness of breath, weakness, and fatigue); also known as the silent killer if acute
Also, the leading cause of death in 2011
Used a dead heart of a rat, washed the organ with a detergent to wash away all cells to leave a gelatin-framework that was used a mold for stem cell heart; was injected from heart cells from newborn rats; rat hearts can be used by humans, but use pig hearts that are similar to humans; stem cells might be able to help build new organs, not just pieces to fix
- Can also help organ donor transplantation; thousands of patients are waiting for organs each year and die before receiving the transplant
